Late-Onset Group B Streptococcal Septic Arthritis of the Shoulder and Proximal Humeral Osteomyelitis Presenting With Reduced Spontaneous Arm Movement in an Afebrile Infant
- 1Department of Pediatrics, Kariya Toyota General Hospital, Kariya, JPN
Abstract
We report a case of a one-month-old girl with late-onset group B Streptococcus (GBS) septic arthritis of the shoulder and proximal humeral osteomyelitis who presented with persistent reduction in spontaneous movement of the right upper extremity without fever, swelling, erythema, or warmth. Initial radiography showed no fracture, dislocation, or bone destruction. Because the reduced arm movement persisted, magnetic resonance imaging (MRI) performed approximately three weeks after symptom onset revealed findings suggestive of right shoulder septic arthritis and proximal humeral osteomyelitis. Blood and joint fluid cultures yielded Streptococcus agalactiae, identified as serotype III, confirming GBS bacteremia and septic arthritis, whereas proximal humeral osteomyelitis was diagnosed based on MRI findings. She underwent surgical irrigation and debridement followed by six weeks of antimicrobial therapy. Her right upper-limb function gradually improved, and no functional asymmetry was observed at two years and one month of age, although delayed development of the proximal humeral epiphyseal ossification center had been noted. This case emphasizes that late-onset GBS osteoarticular infection should be considered in young infants when unilateral reduction in limb movement persists for several weeks, even in the absence of fever or overt local inflammatory signs.
Related
- Possible Pediatric Autoimmune Neuropsychiatric Disorders Associated With Streptococcal Infections (PANDAS) Presenting in Late Adolescence and Early Adulthood: A Case Series.
- Salmonella Osteomyelitis with Cutaneous Fistula in an Immunocompetent Adult Presenting as a Tumor-like Bone Lesion
- Epidemiology and outcomes of Group A streptococcal and non-Group A streptococcal septic arthritis in French children between 2010 and 2023, a national cohort analysis, and case-control study
- C5-Predominant Segmental Zoster Paresis Presenting With Right Shoulder Abduction Weakness Before Cutaneous Eruption: A Case Report
- Case Report: Atypical cat-scratch disease presenting as referred shoulder pain and deep lymphadenopathy in a pediatric patient
BibTeX
@article{yamaoka2026lateonset,
title = {{Late-Onset Group B Streptococcal Septic Arthritis of the Shoulder and Proximal Humeral Osteomyelitis Presenting With Reduced Spontaneous Arm Movement in an Afebrile Infant}},
author = {Ayaka Yamaoka and Soichiro Ishimaru and Taichi Kobayashi and Kentaro Suzuki and Shun Imamura},
journal = {Cureus},
year = {2026},
month = sep,
doi = {10.7759/cureus.116981},
url = {https://doi.org/10.7759/cureus.116981},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Late-Onset Group B Streptococcal Septic Arthritis of the Shoulder and Proximal Humeral Osteomyelitis Presenting With Reduced Spontaneous Arm Movement in an Afebrile Infant
AU - Ayaka Yamaoka
AU - Soichiro Ishimaru
AU - Taichi Kobayashi
AU - Kentaro Suzuki
AU - Shun Imamura
PY - 2026
DA - 2026/09/26
JO - Cureus
DO - 10.7759/cureus.116981
UR - https://doi.org/10.7759/cureus.116981
AB - We report a case of a one-month-old girl with late-onset group B Streptococcus (GBS) septic arthritis of the shoulder and proximal humeral osteomyelitis who presented with persistent reduction in spontaneous movement of the right upper extremity without fever, swelling, erythema, or warmth. Initial radiography showed no fracture, dislocation, or bone destruction. Because the reduced arm movement persisted, magnetic resonance imaging (MRI) performed approximately three weeks after symptom onset revealed findings suggestive of right shoulder septic arthritis and proximal humeral osteomyelitis. Blood and joint fluid cultures yielded Streptococcus agalactiae, identified as serotype III, confirming GBS bacteremia and septic arthritis, whereas proximal humeral osteomyelitis was diagnosed based on MRI findings. She underwent surgical irrigation and debridement followed by six weeks of antimicrobial therapy. Her right upper-limb function gradually improved, and no functional asymmetry was observed at two years and one month of age, although delayed development of the proximal humeral epiphyseal ossification center had been noted. This case emphasizes that late-onset GBS osteoarticular infection should be considered in young infants when unilateral reduction in limb movement persists for several weeks, even in the absence of fever or overt local inflammatory signs.
SN - 2168-8184
ER -